This invention relates to miniature snap action switches, often known as micro-switches. These generally require only a small force for operation but there is a requirement in certain fields for the operating force to be even lower than that which is normal at present.
This has previously been achieved by making the snap-action spring, which in one widely used design also forms the moving contact carrier, of a very thin material. The trouble with this is that, by weakening the carrier, one is also reducing the contact pressure, and also the pressures with which the limbs of the carrier engage in their locating abutments. This reduces the effective electrical rating of the switch, because of increased heating at these points, and the switch may also behave badly in conditions of vibration, since the contacts can be vibrated apart.
To reduce the operating force by increasing the leverage is no answer because the increased leverage means increased travel of the external actuating element.